Stupid question and and the risk of sounding like a dick ...

Is it just a straight replacement for a derby cover on a 103 Evo engine? I've done one on my Sportster and there's no gaskets to worry about. Is it the same on a Street Bob? It's not the timing / clutch cover which definitley needs a gasket, I know.

 

Derby/clutch covers are one-in-the-same...I always replace the gasket, but that's just me. IMO...$5 insurance on no future leaks. Others have reused gaskets w/no problems...your choice.

 

reuse the gasket you have unless you damage it, or just have extra money to throw away.

 

I re-use mine but I do have a spare in my parts drawer, just in case...

 

I have always reused the gasket. I put over 42000 miles on my 04 Electra Glide and reused the same gasket every single fluid change- never a leak.

Edit- obviously I inspected it every time, If its nicked or torn replace it. If its in good shape slap it back on and go

 

timer cover has no gasket. no fluid behind it.

the derby cover/clutch cover is either going to have a pancake gasket, or an orange 'quad ring' (like a big o-ring only squared off). if your derby cover does not have the groove for the quad ring, then you don't have a choice on which one to use. but, either way, you can get multiple uses out of it. only used the pancake gasket once, on someone else's bike, but on mine, I had over 40,000 miles, which equates to 8 oil changes and never replaced the quad ring and had zero leaks.

the fluid behind the gasket is not under high pressure, and the bolts are not high torque. should be good to go for a number of changes.

 

I've never had any issues with either style.

As mentioned, if the Derby cover of your choice does not have the groove machined into it, you have no choice but to use the flat pancake style.